The present invention pertains to a seal ring for axially sealing two parts arranged so as to be able to move axially with respect to one another, and a seal system with two parts arranged so as to be able to move axially with respect to one another and being axial sealed. The invention further relates to a method for making a seal ring for axially sealing two parts arranged so as to be able to move axially with respect to one another, and a method for operating a seal system with two parts arranged so as to be able to move axially with respect to one another and axial sealing.
Seal rings are known, such as K rings or rings having a K-shaped profile, for applications in radial sealing of parts able to move relative to each other. DE 103 27 777 A1 discloses a sealing arrangement for the sealing of two parts able to move axially with respect to one another for a radial sealing application.
The problem which the present invention proposes to solve is to create an improved seal ring for axially sealing two parts arranged so as to be able to move axially with respect to one another, and an improved seal system with two parts arranged so as to be able to move axially with respect to one another and being axial sealed. The present invention further creates an improved method for making a seal ring for axially sealing two parts arranged so as to be able to move axially with respect to one another, and an improved method for operating a seal system with two parts arranged so as to be able to move axially with respect to one another and axial sealing.
This problem is solved by a seal ring for axially sealing two parts arranged so as to be able to move axially with respect to one another, and a seal system with two parts arranged so as to be able to move axially with respect to one another and being axially sealed in accordance with embodiments of the invention. The problem is also solved by a method for making a seal ring for axially sealing two parts arranged so as to be able to move axially with respect to one another, and a method for operating a seal system with two parts arranged so as to be able to move axially with respect to one another and axial sealing according to embodiments of the invention.
According to embodiments of the present invention, an axial sealing can be accomplished, wherein in particular two fluid volumes can be sealed against one another, of which one of them can be subjected to an excess pressure. Thus, for example, one side of a seal ring can be subjected to pressure in order to accomplish an axial sealing between surfaces of two parts, which can have a relative axial movement with respect to one another. The seal ring in particular can be designed as an axial K ring.
Advantageously, according to embodiments of the present invention, a reliable axial sealing can be accomplished even if the two seal surfaces have a high tolerance with respect to one another. An axial K ring as the seal ring or seal element can offer technical and economic benefits, especially during applications in which a tolerance of a spacing between two parts being sealed is too great for the use of an O ring. The technical benefits can consist, for example, in that an axial seal according to embodiments of the present invention in a state not subjected to pressure exerts no axial load on the opposing surfaces or the two parts being sealed and, in a state subjected to pressure, it only exerts a relatively slight axial load on them. Moreover, in the opposite direction a venting of air through the seal can also be made possible. The economic benefits may consist, for example, in that existing parts can be used without modification, especially in the case of an application with a check valve and a solenoid, especially without modification of the solenoid part. For example, it is also possible to refrain from plunging the magnetic core into the check valve in order to seal off the parts with a radial sealing, or to narrow a length tolerance for the parts being sealed off. The axial sealing according to embodiments of the present invention can also be employed generally in applications where an axial seal is required when there is a relatively high tolerance on the spacing of the two parts from each other and also an excess pressure on only one side.
The seal ring for the axial sealing of two parts arranged so as to be able to move axially with respect to one another has the following features:
a) two sealing lips, which are arranged circumferentially on an axial first end side of the seal ring, wherein the sealing lips are designed such that they can be spread apart from one another by a first fluid pressure of a first fluid volume so as to bear in a sealing manner against mutually opposing sealing faces of a first of the parts; and
b) a sealing projection, which is arranged circumferentially on a second end side of the seal ring, oriented axially away from the first end side, wherein the sealing projection is designed in order, when in a state bearing against a sealing surface of a second of the parts, to seal the first fluid volume in a region arranged radially inward with respect to the sealing projection against a second fluid volume at a second fluid pressure in a region arranged radially outward with respect to the sealing projection.
The first part can be a valve, for example, especially a check valve, and it can have a double check valve, for example. The second part can be, for example, a solenoid, a magnetic core, a magnetic core arrangement or the like. In particular, the seal ring in combination with a sealing system can be used in an application for electronic fluid level control of a vehicle trailer, for example. In this case, the seal element can be used to provide an axial sealing, especially between a double check valve and a magnetic core tube. The seal ring in this case can be designed in particular as an axial K ring or a K ring for axial sealing or a seal ring with K-shaped cross section profile for axial sealing. The seal ring can be designed so as to seal off the first fluid volume, which can be arranged in the region of the first end side as well as in a region of the second end side arranged radially inward from the sealing projection, and the second fluid volume in a region of the second end side arranged radially outward from the sealing projection, from each other. The two opposing or parallel sealing faces of the first part can be oriented slanted or normal with respect to the sealing face of the second part. The sealing projection can be formed by two partial portions of the second end side of the seal ring which are sloping with respect to the sealing projection.
According to one embodiment, the seal ring can be designed such that, when a fluid pressure gradient is present between the first fluid pressure of the first fluid volume and the second fluid pressure of the second fluid volume, the first fluid pressure being greater than the second fluid pressure, it can move axially in the direction from the first end side toward the second end side with the sealing projection into a sealing position bearing against the sealing face of the second part. When the fluid pressure gradient is present, the sealing lips can be designed to be pressed into a sealing bearing position against the opposing faces of the first part. Such a design affords the advantage that the pressure difference can be used to accomplish a reliable sealing which is reversible upon removal or reversal of the pressure gradient.
The sealing lips can also be designed to subtend between them an acute resting opening angle in a non-installed state of the seal ring. The resting opening angle here can be greater than 30 degrees, for example, especially 40 degrees or more, and merely as an example it can be less than 70 degrees. The resting opening angle can alternatively also be an obtuse angle. Moreover, the sealing lips can be designed to subtend a spreading angle in an installed state of the seal ring which is smaller than the resting opening angle, at least when the fluid pressure gradient is absent. Such a design affords the advantage that a sealing action of the sealing lips can be increased, since their spreading into a position bearing against the sealing faces is facilitated.
Moreover, the sealing lips can be formed from a first elastic material with a first surface roughness in a first surface portion, having end portions of the sealing lips comprising the sealing projection and sealing edges, and a second surface roughness in a second surface portion outside of the first surface portion, the first surface roughness being less than the second surface roughness. The elastic material here can be a plastic material. The surface roughness here can be indicated or characterized by an average roughness value. Thus, the end portions of the sealing lips comprising the sealing projection and sealing edges can have a smaller surface roughness than the remaining surface of the seal ring. Such an embodiment affords the advantage that the sealing action of the seal ring against the sealing lips can be heightened and made more reliable.
A seal system with two parts arranged so as to be able to move axially with respect to one another and axial sealing has the following features:
a) a first part, in which an annular groove is formed with mutually opposing sealing faces;
b) a second part with a sealing face, wherein the first part and the second part are arranged able to move with respect to one another along a mutual axial axis; and
c) a design of the aforementioned seal ring, wherein at least the sealing lips of the seal ring in the groove of the first part and the sealing projection of the seal ring are or can be arranged bordering on the sealing face of the second part.
In connection with the seal system, an embodiment of the aforementioned seal ring can be used advantageously to produce an axial sealing between the parts or the fluid volumes.
According to one embodiment, at least one through opening can be provided, which is formed in the first part between the groove and a chamber which can be subjected to the first fluid pressure of the first fluid volume. The at least one through opening can represent a flow connection between the chamber and the groove. The at least one through opening can emerge into a surface portion of the groove which is separated or spaced apart from the opposing sealing faces of the groove. Such a design affords the advantage that the first fluid pressure can be used to move the seal ring in the axial direction toward the second part, in order to press the sealing projection into a position reliably bearing against the sealing face of the second part.
In particular, the first part can be a valve and the second part can be a solenoid. The valve can be a check valve, especially a double check valve. The solenoid can be designed as a magnetic core, a magnetic core tube, or the like. For example, the valve and the solenoid can be suitable for, or used for, a fluid level control of a vehicle trailer. Such a design affords the advantage, in particular, that no design changes are needed for the solenoid or existing magnetic core arrangements can be used without change and thus costs can be saved when using the seal ring according to embodiments of the invention.
A method for making a seal ring for axially sealing two parts arranged so as to be able to move axially with respect to one another, has the following steps:
(a) forming the seal ring from an elastic material with two sealing lips, arranged circumferentially on a first axial end side of the seal ring, wherein
(b) the sealing lips are designed such that they can be spread apart from one another by a first fluid pressure of a first fluid volume to bear in a sealing manner against mutually opposing sealing faces of a first of the parts, and with a sealing projection, which is arranged circumferentially on a second end side of the seal ring, oriented axially away from the first end side, wherein
(c) the sealing projection is designed in order, when in a state bearing against a sealing surface of a second of the parts, to seal the first fluid volume in a region arranged radially inward with respect to the sealing projection against a second fluid volume at a second fluid pressure in a region arranged radially outward with respect to the sealing projection.
By carrying out the method, an embodiment of the aforementioned seal ring can be advantageously produced. The forming step in this case can involve a forming process.
In the step of forming, the seal ring can be formed with a first surface roughness in a first surface portion comprising end portions of the sealing lips having the sealing projection and sealing edges, and a second surface roughness in a second surface portion outside of the first surface portion, the first surface roughness being less than the second surface roughness. In this case, the first surface portion and optionally also the second surface portion can be left in particular in a state as delivered or in a rough state and be machined in addition or alternatively without a material removal method. Such an embodiment affords the advantage that suitable surface roughness values can already be established during a forming or reforming of the seal ring, so that further machining steps can be omitted, especially material separation steps.
A method for operating a seal system with two parts arranged so as to be able to move axially with respect to one another and axial sealing has the following steps:
a) providing an embodiment of the aforementioned seal system; and
b) applying the first fluid pressure in the region of the first part, in order to spread the sealing lips of the seal ring into the sealing position bearing against the mutually opposing sealing faces of the groove of the first part and to move the seal ring axially in the direction from the first end side toward the second end side with the sealing projection into a sealing position bearing against the sealing face of the second part in order to seal off the first fluid volume and the second fluid volume from each other.
The operating method can be advantageously implemented making use of an embodiment of the aforementioned seal system in order to seal off the first part and the second part or the fluid volumes from each other.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.